I am replacing the flooring in a bedroom and using a composite "wooden" product. The salesman recommends gluing. So far so good. I imagine the coefficient of expansion of the composite is similar to that of plywood.
But he also recommends leaving 1/2" around the edges (at the walls) for expansion/contraction. This part puzzles me -- how is the flooring material going to move in relation to the subfloor (plywood) if it is glued to it?
This in turn made me reflect that I have installed sold wood (3/4") in the past using a regular flooring nail gun, which would also -- you would think -- create a "crossgrain" issue between the oak flooring (subject to seasonal humidity change) and the plywood subfloor (not so much affected). I left room for expansion/contraction, but it has not been an issue. And in any case, the two products are securely nailed together so where can the expansion/contraction take place?
What am I missing here?